The work proposed in this Phase I application is to construct and characterize a recombinant retrovirus that will be used to express PDGF in cultures of human epidermal cells. The rate of PDGF secretion from these epidermal cells will be measured and the ability of the cells to form an epideris will be assayed by transplantation to the athymic mouse. Future work in Phase II will evaluate the efficacy of transduced epidermal cells delivering PDGF to accelerate wound healing in an animal model of wound healing. The long term objective will be to develop a wound healing product based on sheets of genetically augmented transplantable epidermal cells that function as an occlusive dressing that actively synthesizes and continuously delivers wound healing growth factors in vivo. This cell-based approach to the sustained and local delivery of growth factor proteins will increase patient compliance, reduce adverse side effects, and maximize the therapeutic benefit.